


Forest Revelations

by PineTrain



Category: Gravity Falls
Genre: Alternate Universe - Siblings, Dipper Classic - Freeform, F/M, Mabel Classic, Multi, Reverse Pines
Language: English
Status: Completed
Published: 2017-05-03
Updated: 2017-10-03
Packaged: 2018-10-27 20:11:42
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 7,770
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10815879
Author URL: https://archiveofourown.org/users/PineTrain/pseuds/PineTrain
Summary: This is in the Sibling AU, which combines multiple AUs as one big family. So the rev!twins are Belle and Mason, an older set of twins to Dipper and Mabel.





	1. Chapter 1

**Author's Note:**

> This is in the Sibling AU, which combines multiple AUs as one big family. So the rev!twins are Belle and Mason, an older set of twins to Dipper and Mabel.

Mabel slipped stealthily through the brush of the forest. People often think of stealth as silence, but sometimes it's better to instead ruffle a leaf here, step on a twig there. To be a part of the ambience was effectively “silence” in the wilderness.

And no one knew these trees like her and her twin, Dipper. They both had their particular specialties in regards to this knowledge. Dipper could name anything you could find and then tell you a billion details about it. Mabel, though, she knew how the forest moved, how it breathed, how it lived. If she wanted to be, she was invisible in the forest to anybody besides Dipper.

Dipper wasn't here, though, and Belle wasn't the type to enter the forest often, so there was no concern of being discovered as she stalked her elder sister. Sighting the older sibling enter the treeline had piqued her interest since she was never a particular fan of nature, but what really grabbed Mabel’s attention was Belle’s attire. It wasn't odd to see her dressed elegantly since she and Mason always had a certain flair, but in the woods? It was completely impractical. It was also… sexy.

Mabel didn't often think in those kinds of terms. She had a sense of sexiness, of course, but there's a difference between being somewhat alluring and what Belle had on. The short jacket was typical, but there was quite a large amount of skin showing on her back between where it ended and her underwear began. It wasn't technically underwear but Mabel didn’t know what else to call such a small set of shorts under a translucent silk skirt. Thigh highs drew attention to her shapely legs before ending in a pair of high heels wildly inappropriate for a trip into the wilderness.

Belle wasn't dating anyone. Not to Mabel’s knowledge, anyways, and she didn't know many other reasons to dress like that. Much less in broad daylight, and in the woods to boot. It naturally attracted her attention like a lightning rod. She simply had to know what would make her sister behave like this.

Despite her footwear, Belle waltzed her way through the trees with nary a stumble nor scratch. Mabel always envied her ability to handle things like they were nothing. She was noisy as all hell, though, which made it easy to track her even when stealth necessitated losing direct sight. 

It was during one such moment that Mabel’s ears pricked as Belle came to a halt. She cautiously approached, slipping into a bush the way a squirrel would. Shifting her way gradually to where she could see, she heard a familiar, male, voice speak.

“So you did it after all?”

“I did,” Belle responded, a bit tersely, “And I hope you're pleased, because I feel completely ridiculous right now.”

Mabel reached a small gap in the bush and peered out, her eyebrows raising at the sight of Mason holding Belle close, the cape he wore slightly enveloping her. Perhaps it was because she figured Belle was going to visit a lover that she didn't immediately recognise his voice. She blushed as she realized just how close Mason held his twin. She had to be over thinking things.

“I am,” Mason said with a grin, cupping her chin and leaning close, “You look ravishing.” He pecked Belle’s lips.

Her sister didn't respond, seemingly annoyed, while Mabel clasped a hand over her mouth in shock. Belle might not have liked that kiss, but the lack of a reaction spoke volumes. She HAD to be over thinking this. Belle was just being chill about her twin kissing her. It wasn't like her older sister would've kissed back in other circumstances.

“Oh Belle, you're so adorable when you're irritated,” Mason said, stroking her hair. “You know it had to be one of us, and our deciding game had a 50-50 chance.”

Belle grumbled under her breath, but Mabel saw a smile creep into her features as Mason kissed her cheek. “Okay, you dork. You're right. I just wanted to see you in the skimpy clothes.”

Mabel suppressed a gasp, now clasping both hands over her mouth as Belle wrapped her arms around Mason's neck and kissed him deeply. It quickly grew more heated as she pushed in and the two stumbled from the intensity. Collecting themselves without breaking contact, they had moved in a way that afforded Mabel a perfect view of their intimacy from the side.

Her heart pounded as she watched Mason's hands stroke up and down Belle’s sides, feeling her bare skin. They passed further up and Mabel noticed that under her jacket Belle had on nothing more than a black, silken cloth running from under her armpits and over her breasts to crisscross her collarbone before wrapping behind her neck. Her brother's hands easily slid under it and he gave a quick squeeze before nudging the garment up and over to reveal her bust to the world. Mason tweaked a nipple and Belle squeaked, finally breaking their kiss.

“Naughty boy,” she giggled, her hands drifting down to unfasten his pants.

“Hypocrite,” he said with a smile as she moved his clothes out of the way.

Mabel was transfixed, eyes wide as saucers while she watched her sister take hold of his member. She knew she should probably get the hell outta Dodge, but was too stunned to move. Wasn't what they were doing wrong? Each set of twins in their family were pretty close, but this was a whole other level of close. Not to mention that Mason and Belle were always insisting on following the rules, and incest was a hell of a rule. If anyone would do something like this it'd probably be May and Ty-

Mabel shook her head. She REALLY had to get out of here. Now she was imagining her other siblings doing these kinds of things. A picture of Dipper ran through her head and her heartbeat somehow got even faster. She wondered how likely it could’ve been her and him instead.

A moan caught her attention and she hesitated. Belle’s hand had begun moving slowly up and down while Mason nibbled her neck. He placed his own hand upon her stomach, leaving it there for a moment before rotating it so his fingers slipped into her shorts. As he moved deeper into their confines, Mabel shuffled her thighs together, feeling a tad itchy between the legs while she imagined what her brother's fingers were about to do to their sister.

“Mason,” Belle panted.

“Yes?” he asked.

She shivered and her hand picked up speed, “I need you.”

He ceased his assault on her neck to kiss her lips again. Staring deep in her eyes, he said, “Anything for my Belle.”

Mason left her, removed his cape and tossed it on the ground to serve as a blanket. He kissed Belle a last time before they pulled down their respective pants. She lay on her back, legs spread so he could kneel between them. Looming over her, their gazes never left each other’s as he rocked his hips back and forth. While Mabel couldn’t see it from her angle, she could tell he was rubbing his length against her by their quiet moans that soon turned into a shared gasp when he entered her. The whole time she watched, Mabel couldn’t get out of her head just how much “my Belle” sounded like “Mabel”.

She knew love when she saw it, and she saw it right now in her siblings as they connected body and soul. This wasn’t like the brother-sister love she had ever seen in them before, but there it was. How long had they kept this secret? How many trysts before this one?

She gave a quiet gasp of her own when she touched herself under her skirt. Her hand had moved on its own, or so she wished to believe. In truth, she was more into this than she expected. The embarrassing thought that maybe she would like it if they included her crossed her mind. To hear Mason say “Mabel” in that loving voice and find out if it really did sound like “my Belle.” To be touched by them as sensually as they now touched each other.

“Harder! Faster! Please!” Belle begged. She didn’t seem to mind keeping her voice down as he obliged her demands, grunting as the sound of skin slapping skin grew ever louder. They were deep in the forest after all, and she didn’t know that her younger sister was watching so intently, playing with herself as silently as she could to the erotic sounds of their coupling.

At least, until her head fell to the side and her eyes met Mabel’s, the girl not as hidden as she should be. Mabel squeaked in surprise. She’d become distracted and had come closer to the edge of the bush than was wise. Her hand stopped its movement in her nethers as she realized she was caught.

Mason didn’t notice though, and Belle’s eyes squinted shut when he began moving even quicker, a loud moan leaving her trembling lips. They were coming to the ultimate moment even though Mabel knew she should leave while they were distracted, she stayed, transfixed with wonder at the sight of them. He grabbed Belle’s face and pulled her into a powerful kiss, giving one last fierce thrust before they both shivered with their orgasms, little gasps and groans escaping despite their determined effort to keep their lips locked. Coming down with deep breaths, they pulled away slightly, staring deeply into one another’s eyes.

They didn’t do anything else for a moment, but then Belle twitched her head in Mabel’s direction. Mason cocked his head, then glanced over. Mabel panicked, unready to deal with this. She should have left already, there were so many chances. She started moving backwards, her nervousness completely ruining her earlier skill with stealth.

“Mabel,” Belle called. “Come here.”

Mabel froze, the vocalization of their knowledge to her presence too alarming to react properly. Her mind in a fritz, she gave her usual response when caught, “N-no Mabels here! Just thin air!”

It was a kind of joke in the family. A sheepish response she gave when she was caught with her hand in the cookie jar. For simple things that she’d usually get a simple bop on the head and an exasperated sigh from the person who caught her. In more serious situations, she’d come clean, finding honesty to be more important. This was too serious, though, and she had no idea how to be honest about catching them like this.

“Mabel, it’s alright. Come here,” Mason said gently, but firmly.

Reluctantly, she emerged. Approaching her elders, she looked away red-faced as they cleaned themselves up and fixed their clothes. Belle gestured for her to sit by them and she did so, awkwardly playing with the hem of her skirt and fidgeting. Her movements reminded her of just how damp her panties were and she felt very tense, not helped by how nobody spoke.

“So, Mabel?” Belle asked.

“Um, so, what?” Mabel responded, trying to avoid the conversation as long as possible.

“So, what do you think? About Mason and I?”

“I… I, uh, I think you guys are great and I love spending time with you and think you’re great and that you guys have,” she paused, feeling really hot, “a lot of fun together and that you’re great and-” she stopped rambling when Belle set a hand on her arm.

“I think we get that we’re great, Mabel. How do you feel about what you just saw us do?”

“Um,” Mabel fidgeted some more, “I, er, I… don’t know…”

She was completely on the spot and had no idea how to act. She faintly recognized how rare this was for her since she usually loved the spotlight. She didn’t have Mason and Belle’s elegant mastery in social interactions, but she was great in her Mabel-y own way and normally could sort her way through even awkward conversations with ease. Yet she was totally at a loss now.

But she hadn’t been a few minutes ago. She’d been very certain about wanting to masturbate, even if she wasn’t totally sure why. She remembered that the only reason she had stopped masturbating was because Belle had seen her, but also how she had felt at the thought that Mason might be saying her name when he had spoken.

Mabel teared up a bit, confusion starting to overwhelm her. She wasn’t scared or sad or angry, but she had no idea how to respond to all this. Belle and Mason weren’t saying anything. She loved them both, but thought it had been as her brother and sister. Did she want to be with them the way they just had? She couldn’t be sure. She wished Dipper was here, he always helped her with difficult situations. Belle’s arms wrapped around her and she leaned into the embrace, nestling her head into her sister’s bosom.

“Shhh, it’s okay, I know it’s complicated,” she said, stroking Mabel’s hair. “It was complicated for us at first, too.”

“Are you angry with us?” Mason asked.

“N-no…” she answered quietly.

“Are you disgusted with us?”

Mabel thought a bit more on the topic, Belle’s comfort helping her stabilize her thoughts a bit. She wasn’t sure. Wasn’t incest wrong? But, she’d actually been excited, she admitted to herself. So maybe she didn’t agree with that sentiment. She was supposed to agree with it though, right?

“I… don’t know…?” Mabel concluded.

“Did you enjoy what you saw?”

Mabel shrank into Belle. She’d just admitted it to herself, but now she had to admit it out loud? She didn’t want to lie to them, but didn’t know what to say. Belle started humming softly, and Mabel felt the vibration of her favorite lullaby against her cheek. It calmed her a bit.

“...yes…”

Belle continued humming the song, while Mason said nothing. Mabel was happy that Belle hadn’t stopped since the lack of a response to what she had said didn’t help her get any closer to answers for all the questions still spinning around. The song finally ended though, and Belle spoke up.

“Mabel, what if I said we wanted you to know?”

She was stunned, a twitch shooting through her. They wanted her to know? She thought back to what they said when Belle had first arrived. Mason had said that one of them had to do something. She’d only followed Belle because her clothes were so out-of-character. This meant… had she been lured here?

Mabel pulled out of Belle’s grip, looking at her siblings with shock. The pair had always been consummate tricksters, but this was on a whole other level. She scooched away a bit and they made no effort to stop her.

“But… why?” she asked.

“Because we’ve been watching you,” Mason said. “We think you might be in the same kind of place we were a few years back. We’ve seen how you look at Dipper.”

Mabel’s face quirked incredulously at what he was implying. They certainly had a talent for noticing things, but the older twins had to be wrong. Sure, she and Dipper always got on amazingly, even compared to the other sets of twins. Sure, she always made an effort to spend as much time as she could with him. Sure, he had grown into a physique that was exactly her type and maybe a couple of times she used it as inspiration for alone time. But she didn’t… not like Mason and Belle… right…?

She shifted uncertainly and twiddled her thumbs. “I don’t think of him that way?”

“Perhaps not,” Belle said, “Or perhaps you didn’t notice you did?”

“Ummm…” Mabel mumbled, going over her memories. It had been kind of a long time since she’d gone on a date. And she had been a little annoyed when Dipper spent time hanging out with Pacifica or Wendy, two girls he’d had interest in. And there was that one time she was having fun by herself and it’d been his face and not just his body she’d used as inspiration.

“You’re unsure,” Mason said simply. “It was a bit difficult for us to figure it out ourselves. Belle had an idea though…”

“Mabel. We love you dearly, and we want to help you through this. We have to figure out how you actually feel about Dipper first, but you’re the only one who can really know.” Mabel nodded slowly, listening to Belle as she sorted through her thoughts some more. “So I thought, ‘How about a substitute?’”

“What?”

“Mason’s a bit older, certainly, but we all know how similar our brothers are to each other, just as we sisters resemble each other,” Belle leaned over and stroked Mabel’s face lightly. Her skin tingled under the pressure as she understood what they were getting at.

“I’m dunno,” she muttered, poking her fingers together. It was intriguing, considering the potential realizations she was now dealing with. Still she had to bring up a major hold-up, “I don’t want to get between you guys.” Her eyes popped open and she immediately yelled, “I MEAN IN YOUR RELATIONSHIP, NOT LITERALLY! CUZ OF KISSING OR WHATEVER!”

She dropped her face into her hands after her outburst. She was probably the only one who thought that she might’ve meant that, and what did that mean about her? Mason and Belle chuckled together.

“She’s always so cute,” he said.

“Of course she is, she’s our little Mabel,” she said.

Belle touched her right sleeve and then flung her left hand away with a flourish, a black scarf flowing out with at least an inch of space between it and her fingers. Mabel knew there was some kind of trick to it, though it’s implications were more of a concern right now. The older twins were masters of illusion, and considering what Belle had said earlier, she knew what they were getting at.

“If you’re absolutely against it, say ‘No’,” Belle instructed, very serious, “If you’re curious, though, we can find out how you really feel.”

Mabel thought over all that happened up until now. She was completely lost in terms of how she felt about everything. She wanted answers and, while her siblings might help, only she could give them. Would she ever have noticed any of this if it hadn’t been for their efforts? Would it have been better that way? Was it better that they had indeed done this? She considered these questions deeply and made her decision.

“Okay.” She nodded. “I’m curious.”


	2. Chapter 2

Belle smiled and gestured for her to move to the center of the cape covering the forest floor while Mason trudged off into the woods. Mabel followed her sister’s instruction, sitting as she sat behind her. Belle leaned in and wrapped the black cloth over her eyes, Mabel momentarily feeling her sister’s braless chest against her. She tingled below at the memory of her and Mason making love that had been momentarily forgotten in light of the discussion.

The world now dark, Mabel was more aware of Belle’s hands on her waist, her breath in Mabel’s ear as she whispered, “Just breathe in, and out. Nice, and slow.” Mabel did as instructed and calmness washed over her while they sat silently. Several minutes passed and she felt herself settle. 

“You’re alone in the woods,” Belle continued. “He asked you to come to this spot for something important, but he didn’t say what. He looked nervous.” Mabel’s breath halted as she heard leaves crunching nearby after Belle’s scenario. The steps were inconsistent, like they were unsure.

“Mabel! Y-You came!”

It was Dipper. No, wait, Mason. But he sounded exactly like Dipper! Why did her older brother have to be so good at imitating voices? She didn’t know what to say, so she said nothing.

“Mabel? Is something wrong?” he asked, his voice wavering.

“N-no. Why would something be wrong?” Mabel said, falling in with the plot they had developed.

“Haha! I dunno! Nothing wrong! Just, Iiiii, well, wanted to tell you something really important.” He was probably rubbing the back of his neck in that “sheepish Dipper” sort of way. She heard him approach, still sounding unsteady on his feet. 

“What is it?” she asked as he stopped in front of her and knelt down on the edge of the cape. He fumbled a little, but she sensed him relaxing now that he was on the ground.

“Heh, it’s a little hard to say. Because, y’know, it’s kinda weird. And, um, y’know, I don’t want to make things weird, but I’m totally making them weird, aren’t I? Haha! Sorry, um, so,” he cleared his throat, “I like you.”

“I like you, too, Dipper,” Mabel said automatically. She knew what he meant, but nervousness demanded she pretend she didn't.

“I mean, I like you in… that way…” He took a deep breath, then let it out, “I love you.”

Mabel’s cheeks felt ultra hot. Mason’s imitation was spot on and she could practically see Dipper pushing awkwardly through his confession. Her heart thudded as she searched for a response.

“Dip? You love me?”

The cape shifted as he shuffled closer to her. Mabel flinched slightly, but Belle held her steady. She was glad her sister was there for support.

“I do, Mabel,” he said softly. His hand brushed down the side of her knee, then snapped away quickly, before finally gently settling on top of it. “Sorry, I'm a little nervous, heheh…”

“That makes two of us,” Mabel giggled, laying a hand over his. She knew he'd be looking away bashfully when he said that. And then he would look back at her with that dorky, blushy smile when she gave his hand a squeeze. It was so adorable.

“You're nervous too? Not, um, angry?”

Maybe she should be. This was quite a revelation for him to spring on her, and a pretty messed up one by societal standards. But Mabel had never given these much heed, so why start now? She felt a tiny bit queasy, but not in the bad way, more like when she got asked out by cute boys in the past. It was strange in this situation, but exhilarating. No, today would not be the day she gave in to society.

“How could I be angry?” she said cheerily. “You're just crushing on a girl. A girl who happens to be awesome. I'm happy my little bro found someone so cool!”

“Yeah, you're pretty awesome, Mabes. Awesome possum.”

Mabel giggled as butterflies danced inside her. The way she indirectly referred to herself and then he immediately agreed? It was the sort of cutesy thing that got her right in the heart. How many times had they done it in the past? But now it was so different. It was so weird how easy it was for her to fall into the flow of things.

“Mabel, can I, uh, can I kiss you?” he asked, almost whispering.

That took her by surprise. It was one thing to say some cutesy things to each other after he just confessed an illicit attraction to her and it was quite another to act on said attraction. Yet, she kind of wanted to now that it had been brought up. Why not? Everything else about this felt nice.

“I dunno, can you?” she snorted, half at her bad joke and half at how strange this day had become.

Dipper snorted too and she felt his hand move out from under hers. As it traced up her arm, she remembered it was her older brother, not her younger, who was doing this. She didn't care. Whatever her weird feelings before had been, as far she was concerned right now it was Dipper cupping her cheek and leaning in towards her. They had said this was about finding out how she felt about him, after all.

He paused just before his lips reached hers. The small, nervous wavers in his breath were warm and gentle, but made her impatient. She closed the gap his hesitation had created and felt a tingle in her body at sensation of the kiss. He began pressing into her earnestly, a powerful passion flowing from him that made her want to laugh with happiness. She fought the urge since she really did want this to end yet.

Her siblings had been right about her. Kissing Dipper felt amazing. Before today, she wouldn't have considered the thought in a million years, and now, after a few short seconds, it felt as natural as if she'd done it for years.

"I told you she’d have to kiss him,” said a male’s voice. 

Mason’s voice. But wait, wasn’t she was kissing him? He was pretending to be Dipper, right? And their lips were currently locked, right?

Her blindfold flung off and she pulled back to see Dipper, eyes wide with surprise. Mason sat behind him, holding another blindfold with a huge grin.

“Yes, yes, and I agreed with you, dork. You can’t say ‘I told you so’ when someone agrees with you,” Belle said.

“Buh-buh-but? Y-you said it was going to be Belle pretending to be Mabel!” Dipper sputtered, turning to stare at their brother.

“So I did,” Mason answered, “And yet here we are.”

There was a moment of silence. Mabel’s expression turned to a flat frown as she saw how Mason and Belle had tricked the two of them. She was only really half-surprised, she figured. Considering their mischievous nature, she should've known they'd been up to something more. Still, though, didn’t that mean-

“You love me?” she asked Dipper.

“Well… yes. I do,” Dipper said, rubbing his arm as he looked back at her, “And you, um, love me, right?”

“Y-yeah, I think I do. It’s all kiiinda sudden. But I... I dunno, that kiss was really nice. I’m kinda happy it was you and not Mason. Or pfff, I’m really happy it wasn’t!”

“See,” Belle said, giving Mabel a hug from behind, “Aren't you both glad we tricked you? Would you have ever even known if we left you to your own devices?”

“Oh, I bet Dipper would have figured it out eventually,” Mason answered, putting his hand on Dipper’s head and shoving his hat forward over his eyes. “He loves solving mysteries, after all. I doubt he would have acted on it, though.”

“Probably not. He is such a panicky little kitten,” Belle agreed. Mabel saw his nose twitch and suspected he was trying to stave off any risk of sneezing. Her own ears twitched as Belle continued, “Mabel, though, she would make a move if she knew. She didn't seem likely to notice, unfortunately.”

“Indeed.”

The older twins stood up and stepped to the side. Dipper and Mabel watched as they embraced and shared a short kiss. Turning towards the younger siblings, Belle leaned her head against Mason as he held her close with one arm. She found his free hand with her own and interlaced their fingers, holding the combo close to their chests.

“Oh, Mason!” she said dramatically. “Look at them. So cute. So naive.”

“How fortunate they are to have us help them find their way,” he said with a sage nod.

“And yet! Young love! Their kiss, so beautifully passionate! Two souls sharing that wonderful fire for the first time as we did so long ago!”

“The world would have been lesser without it.”

Mabel didn't mind their teasing too much. It was a bit embarrassing for them to overdramatise it all, but she really had enjoyed the kiss. She glanced over at Dipper, who was very obviously not handling the teasing words as well as she was. He stared down at his twiddling thumbs, tossing little glances of his own in her direction. Their eyes met during one, though, and a small grin crept over his face.

“Lesser, yes! We have truly done a great deed in bringing our siblings together as was meant to be. There is so much to thank us for!”

“But of course, dearest sister. And so, we come to the matter of payment.”

Dipper and Mabel broke their eye contact and looked up at them. Mason and Belle’s eyes seemed to glow lightly (a trick of the forest light, probably) and they wore wicked grins. A predatory aura exuded from them as they stared hungrily at the other pair.

“Payment?” Dipper asked.

“Yes, payment,” Mason responded.

“Like money?” Mabel said, confused.

“Not quite,” Belle snickered. “Money would somewhat dirty this pleasant little event, don't you think? Make it like a business transaction. Where's the romance in that?”

“No, we had a different idea,” Mason said. “Mabel. What were you doing while you watched us? You said you enjoyed it.”

“Oh! Um! Uh!” Mabel panicked. It was obvious they knew she’d been masturbating, but she couldn't just say it with Dipper right there! She’d only just kissed him a couple minutes ago, she wasn't ready to talk about playing with herself. She studiously avoided looking in his direction as she searched for what to say.

“Wait. What happened?” Dipper piped up. “Were you guys doing something before I got here?”

“We were doing the same thing you watched us do two months ago. The same thing we were doing a few weeks later when you caught us again,” Mason said matter-of-factly. “Did you think we didn't notice?”

Mabel finally found it within her to look at her brother. His eyes were as big as sauce pans. Evidently he had, in fact, thought that.

“You saw them having s- er, making love, too?” she asked, surprised.

“Oh, Mabel,” Belle giggled, “I can assure you we were definitely ‘having sex’ when he saw. I do appreciate that you know the distinction as today was certainly more of a ‘making love’ situation. It's easier to be careful when we don't let our passion get a hold of us and I highly doubt Dipper would have caught us either time if we hadn't been so distracted.”

“A bit shocking, I will admit,” Mason mused, “to find some evidence on the floor outside the room after the fact. It wasn’t hard to figure out who left it after Dipper started behaving shifty around Belle and I.”

“Evidence?” Mabel asked.

Belle smiled broadly, “He got quite a bit further than you did, dear. As I said, we were somewhat more raunchy when he watched. It must have excited him quite a lot!”

Mabel stared over at Dipper, but it was his turn to avoid looking at her. His head looked like a kettle about explode from heat with all the red on his skin.

“But he didn't bring it up, and he didn't tell anyone,” Mason continued. “So we watched him. And we saw him start watching you. Looking back, there was always a little something different in how he looked at you, but it's not the sort of thing you notice unless you're looking for it. Perhaps because he didn't know he was doing it until he saw us. Once he had, he started wondering and it became more obvious to both him and us.”

“It was true for you today, too. Right, Mabel?” Belle asked. She nodded. “Yes. Once we saw it in Dipper, well, it wasn't hard to see in you too, since we knew what to look for.”

“And so I decided to approach him. I had to be careful because-”

“Oh, shush!” Belle interrupted her brother. “You just like hearing yourself talk! We don't need to go over the whole plan like supervillains. I believe they've got the gist of how it worked out. Let's get back to payment!”

“You’re just horny,” Mason grumbled, looking aside.

Mabel leaned back a bit. She now had an idea of what the cost was. Belle caught her eye and saw the realization in it.

“Yes, Mabel, you’ve got it, don't you? Or, you're not totally sure what ‘it’ exactly is.”

The older twins let each other go and moved to the opposite sides of the cape than they had started. Mabel spun to keep Mason in front of her, and she felt Dipper do the same behind her with Belle, putting them back-to-back. They swooped in, and Mabel flinched a little as Mason reached out to stroke her hair. She wasn't afraid, just nervous and confused.

“So, you both liked what you saw. Enough to have a little ‘fun time’ while you watched,” Belle cooed.

“And you were both willing to kiss us. You thought we were pretending to be your twin, but, aside from our trick, you ‘knew’, deep down, it would be us,” Mason said, his voice laden with accusation.

“What does that mean, we wonder?”

Belle’s voice was like silk in her ears and Mabel shivered as Mason's hand drifted down her cheek and passed over her neck. It reached her shoulder and he pulled gently, his eyes boring into hers. She followed him as he drew her close and turned her around. He was now behind her in the same way Belle had been earlier and Dipper was in the same with the older girl.

They shared a glance, then simultaneously noticed Belle and Mason doing the same. Theirs wasn't uncertain, though, instead carrying a definite plan of action. Belle grinned and leaned her mouth to Dipper’s ear. Mabel couldn't hear her well since she whispered, but Dipper looked embarrassed as her lips grazed his skin while she spoke. A feeling Mabel was soon familiar with as Mason did the same to her.

“She’s beautiful, isn't she? My Belle? It’s so much like ‘Mabel’, the way I say it. You thought that, didn't you? While you watched. Did you wonder what it'd be like if you were in her position?”

Mabel didn't answer. He had her to a T. Right down to his hands passing over her body and making her skin tingle even through her clothes. She felt hot and could tell Belle was reading Dipper just like Mason read her. Was she whispering memories of the trysts he had seen to him?

“Are you jealous? Seeing her touch him like that? You only just found out you love him. You’ve only kissed once.”

Mabel hadn't thought of that. She’d been so distracted she hadn't realized that Belle was doing something hella inappropriate to another girl’s man. And that was ignoring the incest aspect!

She did feel a bit angry now that the thought was in her mind, but it didn't feel too intense. Maybe it was because Mason was feeling her up the same way and she’d be a hypocrite. She caught Dipper’s eyes again and they stared for a beat. They were both in the same dilemma and felt the same way.

“Yes,” Mabel muttered.

Mason hummed to himself, then nipped her ear. He held it for a second, then lapped his tongue across the bit of flesh between his teeth and let go. “Watch her,” he said.

Mabel stared at her sister, though her focus was shaken by the sensation of what he'd done. She didn't know what she was supposed to be looking for, since Belle was acting just the same. But then, for just a split second, her eyes snapped up towards Mason before returning her attention to Dipper.

Mabel would have missed it if she hadn't been ready. It was weird, the sight of jealousy in her sister’s eyes for that brief moment. This might actually be the first time she'd ever seen it. Belle didn't get jealous, as far as she had known. If she wanted something, she took it, by whatever means necessary. You can't be jealous when you always get what you want, after all.

And now Mabel herself was the source of jealousy. How unexpected. She’d never seen this kind of weakness in her sister and now she's a part of it. A soft gasp drifted from Dipper’s mouth as Belle’s hands slipped between his legs, pulling them open before one passed over the bulge in his shorts.

“I’m the same, of course,” Mason said, biting Mabel’s neck and eliciting a gasp from her as well. “But isn't it interesting? She looks so much like you. It's almost like watching yourself touch him.”

Mabel gulped. He was right. It was similar to the kissing trick, except this time she thought of Belle as herself. If she ignored the slight discrepancies their age difference brought, if she imagined she was wearing Belle’s clothes, then wasn’t it like she was looking in a mirror? Like it wasn’t her sister doing these things to him? That those were her hands on Dipper’s body?

Or like it was his hands on hers. She couldn't see Mason, so it was even easier to imagine that he was actually Dipper. Mabel’s breath quickened as a hand slipped under her sweater and she felt his skin on hers. She closed her eyes, enjoying the sensation of fingers drifting over her stomach. They were careful, like their owner wasn't sure of himself; and yet, at the same time, they flickered with eagerness to explore further. She could tell he hated his own paranoia despite how much he indulged in it, the conflict as frustrating to himself as it was to her.

She reopened her eyes, suddenly wary the older twins had somehow pulled another fast one and it really was Dipper feeling her up. But no, she saw him before her, leaning against their sister as she visibly tweaked a nipple under his shirt. His mouth scrunched and Mabel smiled. It was a weak point she’d have to remember. Not an easy task as she felt a hand slip under her bra and give her a tweak of her own.

Mason’s other hand moved between her legs and she dutifully opened them. His own legs were splayed around her and she reached down to squeeze them to try and ground herself. It was difficult to keep track of things with Mason sucking on her neck again, a finger passing ever-so-slightly up her soaking panties. Then the pause, the endlessly instant pause, before it drifted back down.

The teasing was tit-for-tat across from them, of course. Belle’s hand slipped seductively under his waistband. Passing inch by inch downwards without touching him, then dragging fingers along his length upwards slowly. A light squeeze near the top followed by a soft pump. Then she released him.

Mabel shared a half-lidded stare with Dipper. Their thoughts were muddled, lost in the haze of their siblings’ ministrations. She watched Belle pull her hand out of Dipper’s pants just as she felt her skirt being pulled up. Her sister unzipped him while her brother helped her raise her hips so he could pull her panties down.

Mabel and Mason were slightly ahead of the other pair. She felt the faintest twinge of Alpha Twin pride at that before his fingers touched her lips and shocks flew through her body. She’d never had anyone else touch her down there like that and it was alarming. New, strange, yet wonderful. She reveled in the twinges of pleasure as her brother gently explored her.

Even with her distraction, Mabel managed to see her sister free Dipper from the confines of his clothes. She would've been surprised to see his cock pop out normally, but at the moment, with a finger running ever smaller circles around her entrance, she simply marvelled at how much bigger he was than the last time she'd seen him naked years and years ago when they were mere children. 

She squinted her eyes shut as Mason's finger, completely lubed with her juices, finally slipped inside her. It was only the barest tip of it, but it somehow felt enormous, like her body recognized a major line had been crossed and over exaggerated the sensation accordingly. When he pulled out, then slipped in further, it felt a bit more realistic, yet still strangely large.

Mabel peaked an eye open to see Belle’s slender hand moving smoothly up and down Dipper’s shaft. If a finger felt this big, how would that ever fit inside her? She looked up at Belle, remembering the sight of Mason thrusting into her, the sounds of her moans and how she called out to him for more. 

The girl noticed her stare and grinned. She waggled her eyebrows knowingly, then glanced down at Dipper’s dick. Mabel watched as she squeezed him tightly at the base and pulled slowly up. Reaching the top, a gem of precum emerged from the tip, quickly softening away as a trickle. She realized that he’d been leaking the sticky fluid already, the head of his cock catching the light with a gleam as Belle swirled her palm around it to provide a degree of lubrication.

Dipper grunted and his hips bucked at the attention. She would have to remember that move, since he apparently liked it. Mabel realized that was an odd thought to have, considering how new all this was for her, but the dizzy feelings in her lust-drunk mind made it difficult to properly care. Instead, she found herself wondering if Dipper was taking his own notes as he watched their brother draw a lazy circle around her clit.

They were were both trapped in the momentum of their siblings’ plan. Cute little toys they loved playing with, especially in this new little game she and Dipper had been drawn into. Mabel saw it in her sister’s eyes as she watched him from the corner of her eye, felt it in her brother’s lips as he nibbled and kissed her neck.

His finger slipped into her again and Mabel moaned aloud. She was getting close, so very close, and she pressed back against Mason in a desperate, instinctive attempt to give him better access to her body. She felt the finger go deeper, then push up inside her. She gasped as he rubbed small circles around a spot she’d only discovered a few months ago. She might have wondered how he found it so much more quickly if it hadn't been just what she needed to go over the edge.

Her legs spasmed and her hips bucked. Waves of pleasure were flowing from her core and crashing through every bit of her body. A cry escaped her mouth and she barely heard how it mingled with Dipper’s as Belle stroked him to his own explosive orgasm.

Mabel panted heavily as she came down from her high, her limbs feeling numb and lifeless from exhaustion. Mason removed his fingers from her and squeezed her in a tight, loving hug that made her feel warm and safe. She wanted someone else, though, and she looked up at Dipper.

He was in a similar situation, but Belle had produced one of the blindfolds and was attending to the mess all over his cock. Their eyes met and Mabel flinched towards him. Mason felt the shift and released her from his hold. She crawled to her twin and reached him just as Belle finished her work and let him go as well.

Mabel kind of wanted to kiss him, but she was so, so tired, both emotionally and physically. Instead she took his hand in hers, interlocking their fingers as she turned to the side and leaned into him. He ran his other arm over her shoulder and held her as he slowly lay them down. There, cradled by Dipper, watched over by Mason and Belle, she slept.

\--------

“Now that’s what I call a success!” Belle announced, tittering behind a hand that still smelled faintly of cum.

“We’ll see,” Mason said, his tone measured and even.

Belle rolled her eyes and set her hands on her hips. “What, you think they're going to wake in each other's arms and decide this was all a huge mistake?” she asked dismissively. “Look at them, they're adorable!”

Mason glanced at them, then covered his mouth, an obvious attempt to look like he was thinking and not smiling in agreement with her. He coughed to regain his composure.

“It's a possibility. We did speed things along for them quite a bit and we might have gone a little too far with the payment.”

“Stop being a worrywart. Dipper’s going to handle that role well enough for the lot of us.”

Mason shrugged and looked at their sleeping brother. For as worried as he would no doubt be in the near future, he looked peaceful right now. It was pretty understandable that he’d be so tired after one of Belle’s handjobs. She really knew what she was doing.

“Ah! What was that?!” she exclaimed.

“What?” he asked, turning to find her staring at him with a growing grin.

“I saw it! A little hint of jealousy on your face!” she teased.

“Yes, well, Mabel saw the same thing on yours earlier.”

“What?! You pointed it out to her, didn’t you? 

“You're talking as though you didn’t do the same with Dipper,” he countered.

Belle tittered again. “I guess trying to make fun of jealousy is a bit pointless if we're all feeling it.” She shifted her posture and pointed at him sternly. “But this is just a ‘sometimes’ thing. I'm going to get very pissy with you if I find out you’re sneaking around with Mabel. Or Dipper.”

Mason stepped towards her, taking her hand in his and folding it gently out of the aggressive gesture. His fingers interlaced with her as the younger twins had done and he cupped her cheek, staring into her eyes.

“Likewise, but I don't think we're going to have a problem with that. You're my Belle, after all.”

“I still need to come up with a dorky way to call you,” she laughed. She leaned into his hand, though, and gave his fingers a squeeze of appreciation.

A few seconds passed, and her expression shifted into a more predatory one, much like when she had eyed Dipper and Mabel earlier. She slipped a couple fingers of her free hand into his waistband and pulled, nibbling her lip a bit as she did.

“Why don't we make sure we’ve dealt with this pesky jealousy for sure?”

“Did you have a solution in mind?” asked Mason, raising an eyebrow as he feigned ignorance.

"Oh yes. The best solution,” Belle giggled as she tugged him to a more private part of the forest, “but this time, I get to be on top.”


End file.
